The Broncos were in need of a running back to complement C.J. Anderson after trading Kapri Bibbs to San Francisco in exchange for a fourth-round selection in the 2018 draft. Last year's fourth-round pick, Devontae Booker, was a disappointment as a rookie, averaging a scant 3.5 yards per on 174 carries.

"I always wanted to play for Denver," Charles said Tuesday. "I still feel like I can still play ball."

Charles acknowledged during a Tuesday conference call that his knee was simply never ready to play last season. After a vigorous offseason rehab, though, he's now confident in his knees, declaring himself ready to go.

New offensive coordinator Mike McCoy's vision for Charles is catching passes out of the backfield and attacking defenses up the middle, NFL Network's James Palmer noted after listening to the running back's conference call.

Charles was a bellcow burner in Kansas City, possessing top-end speed and a guarantee to gain chunks of yards. Although he owns the highest yards-per-carry average in NFL history, it's fair to wonder how much is left in the tank after recurring knee injuries wiped out the majority of his past two seasons.

Charles tore his right ACL in 2015 and was slow to return to game action in 2016. The twin knee operations ended his campaign after just 12 carries in three games.

The 30-year-old recently posted a video showing agility work, hoping to quell worries about his health. The Broncos mandated that Charles pass a physical before putting pen to paper on a new contract.

"It's not about money," Charles said. "It's not what you see, it's what you don't see. A lot of people see me [being done]. I see me going out there, helping the team win and helping the team get to the playoffs and get to the Super Bowl. That's what I see. I see things that are just in my fate."